Noon Electronic devices play integral roles in manufacturing, communication, healthcare, commerce, social interaction, and entertainment. For example, electronic devices power the server farms that provide cloud-based, distributed computing functionality for commerce and communication. Devices with computing power are also embedded in many different types of modern equipment, from medical devices to appliances and from vehicles to industrial tools. Additionally, one electronic device—the smartphone—has become a necessity to always have at hand With electronic devices becoming so pervasive, the power consumed by electronic devices has become an issue.
Manufacturers therefore consider anticipated levels of power consumption when designing electronic devices. Motivations for lowering power consumption include reducing cost-of-use and minimizing environmental impact. Furthermore, portable electronic devices are powered by batteries, which have a limited ability to provide energy before needing to be recharged. Thus, a portable electronic device can be used for longer periods before needing to be recharged by reducing power consumption. A lower rate of power consumption can also enable the use of a smaller battery to decrease the size of a portable electronic device.
In electronic devices, integrated circuits and printed circuit substrates, such as printed circuit boards (PCBs) or films, incur a significant percentage of the power consumption. By reducing the energy used by circuits over time, the power consumption of the overall electronic device can be reduced, and battery life can be lengthened. One approach to reducing the energy usage of circuits is to intermittently power down the circuits. Unfortunately, powering down circuits affects their functionality and may therefore impact the capabilities of, or user experience provided by, the corresponding electronic device.
Consider, for example, dynamic random-access memory (DRAM). DRAM is used in many electronic devices to store information, such as computer code and data, because of DRAM's unique combination of size, speed, and cost. A negative attribute of DRAM, however, is that DRAM consumes an appreciable amount of power while being used to store such information. Powering down a DRAM block can therefore save a significant quantity of power and extend battery life. Unfortunately, completely cutting power to DRAM causes the stored information to be lost. Accordingly, to reduce energy usage and extend battery life, designers search for techniques that can enable DRAM to be powered down without losing stored information.
This background description is provided to generally present the context of the disclosure. Unless otherwise indicated herein, material described in this section is neither expressly nor impliedly admitted to be prior art to the present disclosure or the appended claims.